Text of letter to Jim Mather, Scottish Energy Minister, on the proposed Biomass development at Dundee

17 September 2010

I write to you regarding Forth Energy’s proposals for their Dundee Renewable Energy Plant.

Can you inform me if the following general feature of biomass power generation will be considered as part of Scottish Government’s scrutiny of these proposals.

As you will be aware, the "carbon neutral" status of biomass power generation is now being challenged.
I quote, at length from the Manomet study in the US :


"The Manomet study, which is based on a comprehensive lifecycle carbon accounting framework,reveals a more complex picture.

"The study shows that using wood for energy can result in an initial "carbon debt" because burning wood releases more CO2 into the atmosphere per unit of energy than fossil fuels (oil, coal, or natural gas).

"But unlike fossil fuels, forests can grow back and recapture (or sequester) CO2 from the atmosphere.

"Over time, through accelerated forest growth, the carbon debt can be "paid off." After the carbon debt is paid off, if the forest continues to grow, a "carbon dividend" is realized and the use of wood for energy then becomes increasingly beneficial for greenhouse gas mitigation.

"As a result, using wood for energy can lead to lower atmospheric greenhouse gas levels than fossil fuels, but only after the point in time when the carbon debt is paid off.

"Whether or not full carbon neutrality will be achieved in these circumstances will depend on if, when, and how the forest is harvested in the future.

"The most innovative and policy-relevant finding in the report is the "debt-then-dividend" model that shows using forest biomass for energy can increase greenhouse gases for a period of time before it reduces them.

"The length of time it takes to pay off the carbon debt and begin accruing carbon dividends (i.e., greenhouse gas benefits) can vary widely, from five years to many decades.

"The length of time depends on a complex interaction of (1) the type of biomass energy used (electricity, heat, or combined heat and electricity); (2) the fossil fuel that biomass energy.

"As an example, with an electric power plant that relies on biomass using whole trees from natural forests in the Massachusetts region—and not waste wood from tree work and landscaping that has different carbon cycle impacts—the carbon debt period is likely to last for at least 20 or 30 years before carbon benefits begin to be realized.

"In contrast, using forest biomass in thermal applications, such as heating municipal buildings or schools, has lower carbon debts and can provide carbon dividends for the atmosphere sooner, generally within 10 to 20 years."

If, as this report suggests, the carbon debt period associated with electricity generated from biomass may be up to 20 to 30 years, how will these biomass proposals for Dundee be viewed from the perspective of the Scottish Government’s targets of 80 per cent reduction in CO2 emissions by 2050 .

Will you inform me if sustainability of supply, a point that has already been raised by my colleague, Baillie George Regan of Dundee City Council, will be considered by the Scottish Government regarding these proposals.

As you will be aware from media reports, Stuart Goodall, the Chief Executive of ConFr ( The Confederation of Forest Industries) has stated that Forth Energy’s plans to procure in the region of 70-90 per cent of its woodchips from overseas would be "difficult to achieve in the long term".

Confor commissioned a recent study that indicated that the demand for wood that would be required for the proposed biomass plants in the UK would reach 27 million tonnes annually, the equivalent of today’s world trade in wood.


Thirdly, Forth Energy have produced a report from Sinclair Knight Merz into the estimated impact of the proposed Dundee Plant


This reached the following conclusions :

"The residual impact on air quality due to the construction, operation and decommissioning of the Renewable Energy Plant has been assessed and it is concluded that the plant will not have a significant impact with respect to all pollutants. The predicted environmental concentration (i.e. the process contribution plus background levels) are within the relevant air quality objectives and environmental assessment levels for each pollutant considered. Therefore, no significant residual effect with respect to local air quality is predicted."

Their work involved the assessment of the effect of air quality from "point source emissions sources from the main and auxiliary boilers" with respect to the following :

"The emissions considered include the substances associated with combustion: oxides of nitrogen (NOx), carbon monoxide (CO), particulate matter (primarily PM10 and PM2.5 i.e. those particles of 10 ìm and 2.5 ìm aerodynamic diameter or less respectively) and sulphur dioxide (SO2).

"For completeness, to ensure the flexibility of fuels which may be employed, and to cover any potential abatement techniques agreed with the Scottish Environment Protection Agency (SEPA) as part of the Pollution Prevention and Control (PPC) permit application, this assessment also considers emissions of heavy metals, hydrogen chloride (HCl), hydrogen fluoride (HF), volatile organic compounds (VOCs), ammonia (NH3), polycyclic aromatic hydrocarbons (PAHs) and dioxins and furans;

"Emissions of pollutants from road traffic (oxides of nitrogen and PM10) from vehicles travelling to and from the site during the construction, operation and decommissioning of the plant could potentially affect local air quality close to the routes between the site and the main road network;

"Dust generated during the construction and decommissioning of the Renewable Energy Plant could potentially cause a nuisance to local residents, unless properly controlled; and

"Fugitive emissions from the biomass handling and storage could potentially give rise to dust and odours at nearby sensitive locations, unless properly controlled."

Can you inform me what procedures the Scottish Government will undertake to determine whether or not the observations, data, methods of modelling, and assumptions justify or do not justify the conclusions offered by Sinclair Knight Merz.



Back to previous page

Back to website home page